Scroll through to see why these 3 celebs are devoted to taking collagen.

The actress drinks collagen as often as she has coffee (every day). “I wake up between 6 and 7 in the morning and make Bulletproof coffee, which I’m obsessed with,” she says. “I use the Bulletproof brand coffee, grass-fed butter, collagen, protein powder, and MCT oil, plus a little vanilla bean if I’m feeling sassy.”

How exactly has the star improved on the pristine and glowing skin of her days playing Rachel Green? She credits collagen. “There’s a collagen peptide that I’ve been loving—I’ve been seeing a difference!” she said. “My nails are stronger and there’s a healthier…how do you explain it? A glow. It’s sort of that working from the inside-out thing.”